Crypt gall wasps get their name from the galls they induce on oak trees for larval development, infesting the tree in the process. While this does not always impact the trees' health, twig or branch, galls can result in death of the most heavily infested trees.

The new species, which could be called a "hyper-parasite", then parasitizes crypt gall wasps as they, in turn, infest oak trees.

E. set, which is also known as the crypt-keeper wasp, comes from the southeastern United States. The scientists have detailed how it infests crypt gall wasps to develop as a larva, before coming out in a very gory manner, after reaching maturity.

The researchers have found out that females E. set deposit their eggs into the galls created by crypt gall wasps. These larvae then go on to develop into mature wasps by feeding, growing, and pupating on the insides of their hosts. They also manipulate the gall so that the hole through which the gall wasp is set to come out in the spring becomes too small.

When the gall wasp tries to emerge in the spring, its head lodges in the hole, killing it. E. set is then free to consume the gall wasp's internal organs, and emerging from its head case.

This gruesome process has inspired the scientists when time came to find a name for the species. They turned to ancient Egyptian mythology, finding a parallel between the wasp and Set, the god of the desert, storms, chaos and violence.

One legend particularly resonated with them. It is a story about how Set trapped his brother Osiris in a crypt, killed him and then cut him into little pieces which he spread around the Earth – not unlike the "evil" E. set does to the crypt gall wasp.